Green Tea Side Effects: They Exist But Don’t Be Afraid!

Although green tea has many health benefits some serious green tea side effects also exist.

These side effects only occur, if at all, when consumption is high, during a longer period of time. After all, the United States Food and Drug Administration (FDA) wouldn’t categorize green tea as “Generally Recognized as Safe“.

Most of the negative green tea side effects are associated with the caffeine content in green tea.

Green tea side effects: caffeine, the scapegoat.

Some of the negative side effects related to excessive caffeine consumption during a longer period of time are:

Insomnia (unable to fall asleep)

Restlessness

Anxiety

Irritability

Upset stomach (gas)

Nausea

Headaches (from dehydration)

Tremor (uncontrollable muscle contraction and relaxation)

Loss of appetite

Diarrhea

Vomiting

Heart palpitations (a rapidly or forcefully beating heart)

Irregular heart rhythm (arrhythmia)

Increased blood sugar levels

Dizziness

Frequent urination.

Green tea side effects: the rest……

Other green tea side effects are:

1. Allergic reactions

People can be allergic to green tea ingredients such as the tannins or caffeine, identified through unexplained skin rash, hives, itching, swelling of the mouth or throat, wheezing, or difficulty breathing or swallowing.

These exceptional allergic reactions are similar to, say, a peanut, bee sting, or shrimp allergy.

2. Health issues

Some health issues may occur when drinking green tea, such as:

Iron deficiency anemia. Polyphenols (mainly tannins and catechins) found in green tea bind to non-heme iron. Although this anti-oxidative effect is desirable in the fight against cancer,this mechanism may impair the utilization of dietary iron. In other words, polyphenols lower the iron availability and absorption from foods; green tea extract decreased non-heme iron absorption by 28%.Two independent studies involving children from different ends of the world (Great Britain and Saudi Arabia) found they may optimize their iron status by avoiding tea with (or after) meals. The interaction between tea and iron can be mitigated, however, by the addition of high sources of vitamin C or consuming tea between meals.Conversely, a 1998 study argued that the reduction in iron absorption may be of benefit to patients with genetic haemochromatosis.

Thiamine deficiency. Another potential green tea side effect is that green tea reduces the absorption of thiamine (vitamin B), which can lead to a condition known as Beriberi (nowadays known primarily to alcoholics, people on fad diets, or persons undergoing long-term starvation) where one version attacks the cardiovascular system and another version attacks the neurologic system.

Kidney problems. Green tea overconsumption may affect the absorption of oxalates and contribute to the development of kidney stones. Contrary to these results, Curhan et al found drinking tea
(a daily serving of 240 ml) decreases the risk of developing kidney stones by 8%; a study involving more than 81,000 women.

Stomach problems. Dubey concluded in a 1984 study that “tea is a potent stimulant of gastric acid, and this can be reduced by adding milk and sugar.”

Beware of diet teas. There are two types of diet teas: the good and the bad. Beware of the second one containing mostly stimulant laxative herbs; when consumed in large quantities these laxative herbs may lead to (chronic) diarrhea, nausea, vomiting, stomach bleeding/cramps, fainting, dehydration and (chronic) constipation. Read more on Chinese diet teas.

Pregnant or breastfeeding women. Caffeine, catechins and tannic acids are substances linked to pregnancy risks such as miscarriages, low birth weights and fetal neural tube defects. Some health organizations advise pregnant women to limit their caffeine consumption to 300 mg per day. Read more on green tea and pregnancy.

3. Interference with medications

If you are on medication or you have a medical history always consult your medical advisor whether or not to take green tea as it may interfere or interact with certain medications such as antibiotics, sedatives, beta blockers (adenosine), blood thinners (aspirin or warfarin), anti-psychotics (MAOIs, clozapine, or lithium), some cough, cold, and weight loss products.